Back when I played TF2, approx a thousand years ago, I mainly played Heavy. Both the things I really remember from those games involved medics.
1. I was Heavy. I had a medic with me. He took some damage while healing me, so when that fight was over I threw down a sandvich in front of him. He did nothing. I looked at him, looked back to the sandvich and waggled my gun at it. He picked it up and typed in the chat something like “thank you so much, nobody usually pays attention to my health” and it was a sad, sad moment we shared together.
2. Heavy. Again. I’ve got a Medic with me and he’s the best. He’s at my back, following me close but not too close, keeping me topped up and staying out of the way. I see him get headshot by a Sniper after standing still in an open area, so I type in the chat “Hey Gregory, you’re doing really good at this but you need to move around more. Other than that you’re the best Medic I’ve had!” Ten seconds later, somebody types “Gregory’s a bot, dude.” and that was the last game of TF2 I ever played.
I have hundreds of hours as TF2 medic, definitely my most played class in my most played game
But I played a lot on a private server with ~50 dedicated players so things went pretty well overall.